Joe Pa was held accountable. He stopped coaching after the scandal broke loose though he was at the age that he might have retired anyway. He had a sterling reputation before the Sandusky thing happened and now does not. They took his statue down and vacated a lot of his wins. He died not long after the scandal happened, possibly in part because of brokenness he may have felt over it. He was held accountable for looking the other way and not taking things nearly seriously enough.
Ferentz had no idea these intense workouts would cause Rhabdo. Perhaps he should have known it was possible but it wasn't an intentional and reckless effort on his part. Some players were hurt and Ferentz's reputation was hurt by it but by a much smaller degree than Paterno's, as it should have been when one honestly examines the two situations.